Electric arc-lamp.



No. 630,470. Patented Aug. a, |899.

A. sTuTTMANN.

ELECTRIC ARC LAMP.

(Application led Dec. '14, 189B.)

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UNITED STATES PATENT OFFICE.

ALEXANDER STUTTMANN, OF RUSSELIIEIM, GERMANY.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 630,470, dated August 8, 1899.

Application filed December I4. 1898.y Serial No. 699,240. (No model.)

To all w/wm it may concern.-

Be itknown that LALEXANDER STUTTMANN, en gineer,residing at Russelheim-on-the-Main, in the Empire of Germany, have invented new and useful Improvements in Electric-Arc Lamps, of which the following is a specification.

Attempts to fix the luminous point in an arc-lamp by feeding two carbons at an angle toward the same constant burning-point have been unsuccessful for many reasons. First7 in using the ordinary carbons, and particularly cored carbons, a good light cannot be obtained for the reason that two craters are formed in the upper carbon, which also accounts vfor the fact that the proper softening and incandescing of the mass does not take place at the point of contact with the two carbons, toward which point they are pressed by spring power or other means, so that the feed takes place only by lits and starts at the times at which the edge of the crater is breaking away; but it has further been found that carbons cannot be produced with such uniformity or homogeneity as to insure the uniform burning away necessary for a uniform feed, and consequently one carbon soon moves past the other.

The present invention has for its object to completely obviate these drawbacks.

The formation of a central crater the deepest point of which extends close up to the meeting-point of the two carbons may be insured by employing cored carbons whereof what I term the core, for the want of la better expression, is exposed at the side which is situated within the angle which the two carbons form with each other-z'. e., angle of convergence. By corein this case I mean a continuous body ofmaterial inlaid in the side of the carbon and of a substance other than carbon. Such carbons are preferably made of semicircular form in crosssection and placed with the flat sides together. The manufacture of such carbons is more simple than that of the ordinary cored carbons. The fact that the luminous are is kept in the center and that the heat is concentrated close to the point of contact of the carbons insures that the carbon becomes burned at that place and becomes soft, so that the carbons can be fed on toward this point. For

the purpose of preventing with complete certainty all movement of the carbons past each other both carbons maybe transversely luted or serrated on their adjacent sides, so that if at any time the circumstances at the point where the carbons bear against each other should be such that one carbon tends to slip past the other then this carbon would at once catch by the point of its next tooth or serration against the point of the corresponding tooth or serration of the other carbon. Further, the uniform' forward feed of the carbons may be effected7 in case the carbons are formed perfectly homogeneous, by connecting the feeding mechanism positively in such a manner that the corresponding carbons shall advance through equal distances in equal times. Finally, it may be stated that with this arrangement of the carbons the use of a closed air-tight globe containing the entire lamp mechanism is considerably facilitated because it is possible to place the whole mechanism in the interior of a hermetically-closed casing.

In the accompanying drawings, Figure I shows two carbons with their lutings and with the crater formed by them.

Fig-2 is a section th rough the two carbons where they bear against each other. A and A are the serrated carbons, d indicating the serrations, and C is the core.

Fig. .3 shows the general arrangement in a closed casing. The carbons A A are guided in the slotted tubes a a, in which followers Il B are drawn toward their point of intersection by means of the cords Z) b, passing over the pulleys c c and a spring-barrel D.v The same applies to the lower carbons A A, tubes a a', small blocks B B', cords b b', pulleys c c', and the spring-barrel D. The tubes a a are stationary with relation to the globe N. The tubes a' a' and the spring-barrel D are fixed to an arm E of the rod F, which is connected to the soft-iron core M of a solenoidcoil P. The core M is suspended from a lei ver R by means of a spring Q, and to its lower end is connected by a link f a lever g, which by meet-ing a set-screw h limits the ascending movement of the core M. The solenoid-coil P acts in the well-known manner to produce the upward and downward movement of the coro M and serves in a considerable degree to ICO raise the core M, and with it the carbons A A', sufficiently to strike the arc and to allow them to descend again to the proper distance after the luminous arc has been formed.

Now what I claim, and desire to secure by Letters Patent, is the following:

l. In an electric-arc lamp, the combination of a set of converging` carbons meeting at a point each of which carbons has inlaid therein a continuous body of material along its side which is included within the angle of convergence, the said carbons being of the same polarity, with another set of converging car bons meeting at a point each of which carbons has inlaid therein a continuous bodyof lnaterial along its side which is included within the angle of convergence, the said conver-V ging carbons being` of a polarity opposite to that of the first-mentioned carbons whereby an arc maybe maintained between the meeting points of the two sets of carbons.

In an electric-arc lamp, the combination of an electrodo constituted by a set of converging carbons meeting at a point, each carbon having a continuons body of inlaid material along its side lying within the angle of convergence, and a second electrode coperating with the set of carbons to form the arc.

In an electric-arc lamp, employing carbons meeting at an angle, each carbon having a continuons inlaid portion within the angle of convergence, means for preventing the carbons from. becoming displaced comprisingl teeth or serrations located upon the sides of the carbons which lie within the angle of convergence, the said teeth or sei-rations being adapted to engage with each other to prevent the carbons from slipping past each other.

1. As a new and useful article of manufacture, a carbon substantially semicircular or half-round in cross-section with a continuous body inlaid in the side of the carbon corresponding to the diameter of the circle, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ALEXANDER STUF'IMANN.

Wi tncsses:

JEAN GRUND, DEAN B. MASON. 

